This application claims the priority of German Application No.: 103 41 642.0 filed Sep. 10, 2003, the disclosure of which is expressly incorporated by reference herein.
The invention relates to an aerodynamically constructed covering part for the underside of a motor vehicle, particularly a passenger car. The covering part has a vent hole through which a partial flow of the cold fresh air flowing through between the covering part and the roadway during the driving operation is guided to a space which is situated above and accommodates assemblies and/or chassis parts, such as the engine compartment and/or transmission space or the like. The partial flow cools the assemblies and/or chassis parts situated there.
Increasingly, the aerodynamic optimization of vehicles takes place at the underside of the vehicle. Here, it is endeavored to implement an underbody having a smooth-surface covering. However, these coverings have the disadvantage that covered areas heat up more intensely. The reason is the insufficient exchange between, on one hand, heated air in the engine compartment and transmission space and, on the other hand, fresh cooling air. The known vent holes permit the targeted feeding of cold fresh air.
A problem arises, however, when already heated outgoing air mixes with the fresh air provided for the cooling, or when incoming and outgoing air conduction devices have a faulty design or do not exist. Furthermore, the aerodynamic advantages of a smooth underbody are considerably impaired by conventional venting concepts.
From German Patent Document DE-AS 1 286 917, a passenger car is known which is equipped with an aerodynamically constructed covering part on its underside. A grille in the form of several slots is provided below the engine on the covering part for venting the engine compartment.
In this arrangement, during the driving operation, a partial flow of the cold fresh air guided through between the covering part and the roadway is conducted through the slots to the engine situated above.
However, German Patent Document DE-AS 1 286 917 does not contain any information as to how the air heated by the engine is discharged from the engine compartment.
It is an object of the invention to further develop an aerodynamically constructed covering part for the underside of a motor vehicle according to the initially mentioned type such that, when the aerodynamic potential of a smooth underbody is utilized, simultaneously the air flowing through the engine compartment and the transmission space is fed and carried away in a targeted and therefore efficient manner.
According to certain preferred embodiments of the invention, this object is achieved by providing an aerodynamically constructed covering part for the underside of a motor vehicle, particularly a passenger car. At least one vent hole is provided on the covering part, through which a partial flow of cold fresh air flowing through between the covering part and the roadway during the driving operation is guided to a space which is situated above and accommodates assemblies and/or chassis parts, such as the engine compartment and/or transmission space or the like. The partial flow cools the assemblies and/or chassis parts situated there, and at least one suction device is provided on the covering part for carrying away the heated air situated in the space disposed above in the direction of the roadway. The at least one suction device being arranged at a distance from the vent hole.
Other advantageous features of Preferred embodiments of the invention are described herein and the claims.
Important advantages achieved by means of the invention are that, as a result of the arrangement of at least one suction device on the covering part, the air circulating through the engine compartment and transmission space is divided in a defined manner into a cooling incoming-air conduction and an outgoing-air conduction carrying away the heated air. As a result of the spatially offset arrangement of the at least one suction device with respect to the vent hole, it is achieved that only cold fresh air is fed to the engine compartment and transmission space, whereas the heated air flows out laterally beside the vent hole and then flows along the underside of the vehicle and is carried away toward the rear.
The suction effect is created in certain preferred embodiments of the invention by aerodynamically optimized suction gills, which form a vacuum zone at the covering part. Viewed in the longitudinal direction of the vehicle, the transversely extending suction gills are arranged in a spaced manner behind one another and are set against the air flow guided through between the roadway and the covering part. The suction gills extend from the covering part downward in the direction of the roadway and have a blade-shaped cross-section. The shape and the position of the suction gills are adapted to the respective cooling task and have the advantage that the aerodynamic coefficients are impaired only insignificantly.
An embodiment of the invention is illustrated in the drawing and will be explained in detail in the following.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.